1. Field of Invention
The invention relates to an aperture device of a projector and, in particular, to a dynamic aperture device and a projector including the same.
2. Related Art
In the optical apparatuses, such as the front projectors, rear projectors or cameras, the control mechanism of the light flux for generating image with different brightness is indispensable. Take a projector as an example. The light source module generates a monochromatic light, and then the monochromatic light is transmitted to a color wheel to generate color light. The light flux of the monochromatic light or the color light must be adjusted continuously so as to obtain the proper brightness, thereby fitting the requirement of contrast. Therefore, a dynamic aperture device is disclosed for adjusting the light flux continuously so as to improve the image quality.
The light shielding portion and the light permeable portion of the conventional aperture device are not completely symmetric. However, the color wheel is driven by a motor to rotate, so that the conventional aperture device may have vibrations due to the non-balance design. This may cause the malfunction of the conventional aperture device. In addition, since the light shielding surface is irradiated by the light, the heat may be generated and transferred to the motor through the shaft. This may lead to the overheating of the motor and make the motor malfunction, so the heat dissipation is also an important issue.
Therefore, there is a need to provide an aperture device that can provide good heat isolation effect and keep the rotation balance to decrease the vibration and steadily control the light flux.